Martha Stewart’s Polish Mushroom Soup

For as long as I can remember, our family had a delicious Polish mushroom soup on the table for big holidays—Easter, Thanksgiving, and Christmas. My mother, affectionately called Big Martha, prided herself on her version, fragrant with dried porcini, or cèpes, imported from Poland. In later years, when “umami” entered the lexicon of chefs, we joked with Mom that her soup was the finest example of that elusive quality. For this recipe, a well-made beef stock is essential; prepared ahead and frozen in quart containers, rich homemade stocks turn soup-making into a simple task, resulting in the most flavorful of dishes.